Write any two differences between external fertilization and internal fertilization.

Explanation

### Step-by-Step Solution:

1. **Definition of Internal Fertilization**:
- Internal fertilization is the process where the fusion of male and female gametes (sperm and egg) occurs inside the female's body. This method is commonly observed in mammals, birds, and reptiles.

2. **Definition of External Fertilization**:
- External fertilization is the process where the fusion of male and female gametes occurs outside the female's body. This method is typically seen in aquatic animals such as fish and amphibians.

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